skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Scanning transmission electron microscopy studies of high-temperature superconducting yttrium barium copper oxide thin films. [Structure and compositional properties]

Miscellaneous ·
OSTI ID:7040199

The YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} thin films were grown by reactive evaporation, reactive sputtering, and laser ablation. The films, especially those grown by laser ablation, are of very high quality with J{sub c}'s over 5 {times} 10{sup 6} A/cm{sup 2} at 77 K. High-resolution STEM images and x-ray pole figure studies, along with transport measurements on microbridge devices, have shown that high angle tilt boundaries are weak links, which exhibit Josephson junction-like characteristics. Images of (301) zone axis YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} obtained with the STEM have demonstrated for the first time for zone axis oriented crystals the theoretical resolution limit of STEM annual dark field imaging which is {approximately} 40% better than conventional TEM bright-field imaging with the same electron optical parameters. High resolution STEM was used to study the grain structures and the grain-boundary structures of YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} thin films. It was found that grain boundaries are extremely clean in high-quality films without any second phase present. High-resolution STEM was used to study compositional variations at the grain boundaries.

Research Organization:
Cornell Univ., Ithaca, NY (United States)
OSTI ID:
7040199
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English